Interleukin 12 receptor beta 1 (IL-12Rβ1) deficiency results in a wide variety of clinical manifestations, ranging from early death in infancy to asymptomatic adulthood. Patients are frequently infected with mycobacteria, with half developing salmonellosis and a quarter developing chronic mucocutaneous candidiasis (CMC). We present a patient with isolated recurrent candidiasis who has a novel IL12RB1 gene mutation (c.903+1G>T).